US 4,234,899 AGranted

Keyed mounting for orienting optical angular, displacement transducer in rigid magnetic disc memory

AssigneeData General Corporation

InventorsMichael Feldstein, Harold L. Thackaberry

Life of this patent

Estimating the term…

Loading patent…

Abstract

An open loop, stepper-motor-driven, rigid magnetic disc memory apparatus for use with a data processing system. A rigid magnetic disc with high track density is driven by a stepper motor in an open-loop fashion or without servomechanism control. The memory apparatus includes: band structure including a spring bias for coupling stepper motor drive to apparatus supporting magnetic heads above and/or below the spinning disc and for temperature compensating for disc/apparatus expansion and contraction; manually operable control for zeroing the magnetic heads, moving and locking them in the disc's landing zone as, for example, while in transit, and providing a travel limit to head movement when the memory apparatus is operating; keying apparatus for preventing erroneous insertion and mis-alignment of and damage to an optical transducer relative to an optical mask arranged to spin with the disc structure; shim apparatus for precisely positioning the magnetic heads in the spin axis direction; viscously-coupled inertia apparatus for damping the stepping motor's step-rotarymotion; a device for employing spinning motion associated with the disc for cooling purposes; and other structure.

Claims4

Dependent claims

In memory apparatus supported by a base and intended for use in a digital computer system, said apparatus comprising a spinable and rigid magnetic disc for recording digital information, motor means including a spinable shaft for driving said disc about its spin axis, and a transducer system including a transducer for measuring at least angular displacement of said disc from a reference fixed to said base, said transducer system comprising:

a transducer-related disc having means mounted thereon for communicating with said transducer, said transducer-related disc being mounted on said shaft and spinable therewith;
said transducer having transmitting and receiving devices, and oriented to permit passage of said transducer-related disc between said devices to alternately permit and prevent communication between said devices;
and
an upright member for supporting said transducer, said upright member including a base lip for connection to said base, said base and said base lip having keying means for constraining the mounting of said transducer system to said base to a predetermined orientation thereby precluding incorrect insertion or removal, whereby said transducer-related disc is constrained to pass between said devices and damage to said transducer system is inherently avoided.

1 more element

Dependencies are inferred from the claim text.